Ionizing and Non-Ionizing Radiation Study Guide
Radiation- Energy emitted from a body or source that is transmitted through an intervening medium or
space and absorbed by another body. Transmission is in the form of waves but wave/particle duality
under quantum physics.
Radiation is classified as being either non-ionizing or ionizing. Non-ionizing radiation is longer
wavelength/lower frequency lower energy. While ionizing radiation is short wavelength/high frequency
higher energy.
Ionizing Radiation has sufficient energy to produce ions in matter at the molecular level. If that matter
is a human significant damage can result including damage to DNA and denaturation of proteins. This is
not to say that non-ionizing radiation can’t cause injury to humans but the injury is generally limited to
thermal damage i.e. burns.
There is a great deal of information on the above chart. One of the most interesting things is that the
visible spectrum is essentially the divide between ionizing and non-ionizing radiation. This makes sense
clinically when we think of UV radiation causing skin cancer.
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Types of Non-Ionizing Radiation and Their Clinical EffectsReferring again to the chart above we can see that Non-Ionizing radiation comes in the forms of:
1.
2.
3.
4.
5.
6.
7.
ELF (extremely low frequency)
Radio Frequencies
Microwave Frequencies
Lasers
Infrared
Visible Spectrum
Ultraviolet
This list is in order of lowest to highest frequency.
1. ELF
Power plant or line workers
Inconclusive evidence of leukemia link
2. 3. Radiofrequency and Microwave Frequency ExposuresOccupational ExposuresRadar and communications equipment, industrial and commercial ovens
Other Exposures
Cell Phones
Clinical EffectsThere is a great deal of controversy regarding potential cancer risks, particularly with
cell phone use. We know that exposure to radio and microwave frequency sources can
cause burns and clinically this is what you are most likely to see.
4. LASER (Light Amplification by Stimulated Emission of Radiation)
Beams of coherent light with single wavelength and frequency
May be in the IR, Visible or UV spectrum
Eye is most sensitive to injury from LASER
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Four classes by risk of injury:
1. No damage
2. Low chance for damage due to blink
3. A)Cause injury with direct exposure
B)Cause injury even when reflected
4. Requires controls to prevent injury
5. Infrared
Penetrates superficial layers of the skin, causes thermal injury, potential for damage to
the cornea, iris, lens of the eye
Welding, glassmaking, heating and dehydrating processes
6. Visible Spectrum
400 to 750nm wavelengths
ROYGBIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet)
Possibility of retinal injury from 400-500 nm blue frequencies
8. Ultraviolet Radiation
200nm to 400 nm
Bridge between Non-Ionizing and Ionizing Radiation
Three regions
UV-A 315nm-400nm
UV-B 280nm-315nm
UV-C ‹280nm
A and B bands produce biologic effects on the skin and the eyes. Photokeratitis,
conjunctivitis, sunburn, photosensitization reactions, skin cancers
Majority of exposures are to outdoor workers, other exposures include welders, people
who work in drying and curing industries and laboratory, kitchen or medical industries
exposed to germicidal ultraviolet
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Types of Ionizing Radiation and Their Clinical EffectsIonizing radiation is emitted from radioactive atomic structures as high energy electromagnetic
waves (gamma and x-rays) or as actual particles (alpha, beta, neutrons)
1.
2.
3.
4.
5.
Gamma Rays
X-Rays
Alpha Particles
Beta Particles
Neutrons
Penetration of Radiation
Gamma Rays, Xrays and Neutrons Penetrate Body Easily, Need lead to shield for gamma
and x-rays, massive shielding for Neutrons
Alpha and Beta Particles are essentially blocked by the skin with Beta Particles
penetrating more deeply with the potential to cause burns. Alpha particles can be
stopped by paper, Beta by plastic
Alpha Particles can cause significant damage if taken internally, see former Soviet Spy
Radiation Measurement
Roentgen (R)- Describes a radiation field in terms of the amount of ionizations
produced in air, not in common use today
Rad- Conventional unit of absorbed dose of radiation per unit mass.
Gray (Gy) – 1 Gray=100 Rads
Rem- Absorption measure to whole body or specified organ, takes into account
radiation quality, Rem=rads x quality factor, each type of ionizing radiation
has a different quality factor
Sievert (Sv)- 1SV=100 Rem
Ionizing Radiation Exposure Limits
Occupational- National Council on Radiation Protection (NCRP) annual exposure 5 rem
Background Exposure for a US resident is 360mrem
Common Occupational Exposures•
•
Medicine- Radionuclides, X-Ray
Nuclear Power Industry
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•
•
•
Document Dating
Food Preservation
Airplane/Space Flight
Transportation of Radioactive Material
Four Ionizing Radiation Exposure Categories1.
2.
3.
4.
Radioactive Contaminates on Intact Skin
Local Radiation Injuries
Whole Body Exposure
Internal Deposition
Acute Radiation Syndrome
Over 100 rad in a single exposure or within 24-48 hours, progressive predictable series
of signs and symptoms developing over a period ranging between a few hours to several
weeks
Clinical response and prognosis generally depends on damage sustained by
hematopoietic system.
Lethal dose for 50% of healthy humans is 350 to 450 rad (3.5 to 4.5 Gy)
Prodromal Period- 1 to 6 hours after exposure
Anorexia, Nausea, Vomiting, Diarrhea
Initial Symptoms subside after a few hours to two days
Ominous signs include diarrhea, skin erythema, lymphocyte count less than
1000, short or no latent period
Latent Period- Variable in duration hours to 30 days
Manifest Illness
Fatigue, GI symptoms, desquamation, deep ulcerations, bone marrow
depression, Stomatitis, hemorrhagic phenomena
Death or Recovery
CBC normalizes in six months to a few years, Clinical recovery within 6 months,
persistent fatigue
Long Term Effects
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•
•
•
•
•
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Chronic Radiodermatitis
Cataracts
Sterility
Prenatal Effects
Cancer
Genetic Effects
Shortened Life Span
Management of Radiation Exposures
1. Radioactive Contaminates on Intact Skin- Wash skin, do not break skin
2. Local Radiation Injuries- Estimate whole body exposure, wound care, nutritional
support, analgesics, infection control, consultation
3. Whole Body Exposure
100 rem or lessComplete history for record
Advise regarding potential late effects (cancers)
Follow as outpatient, counseling
100 rem to 200 rem
Complete exposure history radiation source and strength
Consider Lab testing CBC with diff
200 rem to 300 rem
Hospitalize
300 rem or more
Transfer to Tertiary Care Center
Supralethal exposure of more than 5000 rem
Supportive care at any hospital will do will die in a few days
4. Internal Deposition
Reduce Absorption- Binding Agents, Antacids
Expedite Elimination- Cathartics
Organ Saturation- Potassium Iodide
Displacement- Calcium, Iodide
Chelation
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